During use, the front surfaces of the taking lenses of one-time-use cameras are subject to contamination by foreign substances. Lenses can be replaced when a one-time-use camera is recycled, or, alternatively, contamination can be removed by a cleaning process.
A variety of cleaning processes are known. U.S. Pat. No. 5,400,098 and U.S. Pat. No. 5,608,486 disclose one-time-use cameras, in which the taking lenses are removed when the film cartridge is removed. Cleaning of separated lenses is fairly straight-forward; however, lens separation adds a risk of loss or damage of the separated lenses and opens up the area of the camera behind the lens to a risk of contamination.
Manual methods of cleaning front surfaces of lenses are well known. U.S. Pat. No. 4,842,132 discloses an example of a device and kit for such manual cleaning. Manual cleaning is slow and inefficient.
U.S. Pat. No. 5,615,395 discloses apparatus and methods for cleaning the front face of a flash reflector cover. In a cleaning head, fabric tape extends over a roller. The roller is lowered against the front face of the flash reflector cover and then the cleaning head or just the cleaning tape is moved back and forth to wipe the front face. Cleanser liquid is applied to the front face or the tape prior to the wiping. During wiping the fabric tape going to and from the cleaning head is kept under tension. Since the front face of the flash reflector cover is generally flat, this approach is not directly applicable to cleaning the curved front surface of a taking lens.
Japanese patent reference JP 10-62915, published Mar. 6, 1998, discloses a method and apparatus for cleaning the front surface of a mounted taking lens. (The term “mounted lens” and like terms are used herein to refer to a lens that has an exposed front surface, but is otherwise held within and enclosed by a camera body or other support structure. A web is supported by rollers over the lens. A rotary head having a flexible brush, is lowered against the web. The brush presses the web down against the lens. The head (or the mounted lens) is rotated wiping the lens. The web is clamped upstream and downstream of the head, prior to rotation. According to U.S. Pat. No. 6,343,185 (at col. 1, lines 49-61), the method and apparatus of JP 10-62915 have the shortcoming that the entirety of the cleaning device must be rotated or the exposure unit on a pallet must be rotated.
Japanese patent reference JP 2001-75241, published Mar. 23, 2001, discloses another method and apparatus for cleaning the front surface of a mounted taking lens. The lens is subjected to high pressure cleaning air and a brush and is then wet by a separate head. Separately, a web is trained over a suction tube by a pair of rollers. The web is moved along the surface of the lens and the moisture is sucked away through the web. The area of contact of the web and the lens is illustrated as being small.
U.S. Pat. No. 6,343,185 discloses a lens cleaning apparatus and method in which a small cleaning head presses a cleaning tape against a taking lens of a one-time-use camera. Only the small cleaning head is rotated relative to the lens. (Cleaning liquid is earlier applied.) Rollers for the cleaning tape are not rotated. The cleaning tape is slackened prior to the rotation and the tape is brought into contact with the taking lens, by the lowering of a cleaner holder plate toward the camera. The cleaner holder plate includes the parts of the lens cleaner other than a set of rollers adjoining the camera. The cleaning tape is clamped upstream and downstream of the cleaning head when the cleaner holder plate is lowered, to keep the loosened part from being retightened by supply and winder reels. Viewfinder lens cleaning is also disclosed. This approach has the advantage that the rotated cleaning head is small. On the other hand, there is the shortcoming that the lowering of the tape against the lens and the slackening of the tape occur as a result of the same movement of the cleaner head plate. The requirements of one constrains the other. For example, wiping is limited to use of a slackened tape.
It would thus be desirable to provide improved methods and apparatus for cleaning a front surface of a mounted lens, in which slackening and tightening a cleaning web does not require simultaneously lowering or raising the cleaning web.